This is a legendary Chilean musical company that was founded in 1969, after their eponymous debut album from 1971 they released many records. I own the one CD version that contains 12 tracks. The songs are recorded during Congreso their tour in 1987, to me the music sounds as a progressive blend of folk and rock, at some moments ir reminds me of Hungarian progrock band After Crying. The band features 9 musicians who play a wide range of instruments, from guitar, cello, flute and saxophone to clarinet, marimba, bass, keyboards and ethnic instruments like the charango (between a guitar and mandoline with 5 double strings) and Andean flutes. The climates range from swinging to melancholic and the compositions sound very melodic and harmonic. My highlights are Dónde estarás? (sound of the charango), Los Maldadosos (propulsive and bombastic atmosphere), the long Coco Loco (virtuosic interplay), Vuelta Y Vuelta (wonderful twanging guitar, warm vocals and nice play on percussion, flute and violin) and the epic Arco Iris De Hollín, the most 'close to progrock' composition: a mellow first part with flute, then gradually more fiery with a powerful and dominant saxophone, at some moments it evokes early King Crimson. When I read that Congreso was added to Prog Archives I was not really thrilled because I am more into vintage keyboard driven bands like Crusis, Blops and Ave Rock but if you like progressive folk music this is a fine band to check out, especially the integration of instruments like the marimba and saxophone sounds interesting. By the way, which Latin-American proghead will add the interesting bands Redd and Vlad V?